A metallic closed cellular material containing organic materials for the smart materials has been developed. Powder particles of polystyrene coated with a nickel-phosphorus alloy layer using electroless plating were pressed into green pellets and sintered at high temperatures. A metallic closed cellular material containing organic materials was then fabricated. On the fabricated metallic closed cellular materials, compressive properties, Young's modulus, ultrasonic attentuation coefficient internal friction were measured. The compressive tests shows that this material has the different stress-strain curves among the specimens that have different thickness of the cell walls. Each stress-strain curve has a long plateau region, the sintering temperatures of the specimens affect the compressive strength of each specimen, and energy absorbing capacity is very high. Young's modulus of this material depends on the thickness of the cell walls and the sintering temperature. The attenuation coefficient of this material observed by ultrasonic measurement is very large. Internal friction of this material is very large and depends on the sintering temperaturer. These results indicate that this metallic closed cellular material can be utilized as energy absorbing material and passive damping material.